can a crash cause hardware failure?

I'm running Ardour 5.11.4 from the Ubuntu repos. I experienced a crash where a note was held on. The panic button did nothing. Since then the mothorboard's onboard audio is hosed. It is simply no longer detected by the OS. The weird part is that my JACK settings use a USB interface for I/O and this device is fine. Is this unusual at all?

Your onboard audio card not being detected by the OS may itself be a software problem rather than a hardware failure. Generally speaking, a software bug would not be capable of damaging your computer's hardware.

A hardware failure could cause the OS to crash however, so it is possible your hardware did fail and you interpreted the causality in the opposite direction, i.e. you asked whether a crash could cause hardware failure, it is much more likely that hardware failure caused a crash.